Urban Spatial Organization, Multifractals, and Evolutionary Patterns in Large Cities

Abstract

Understanding urban spatial organization and evolutionary patterns is critical to formulating spatial development strategies. Multifractal analysis has been effectively applied to investigate urban spatial organization in a multiscale manner. Without effective approaches to deal with local parameters, however, its ability to identify urban spatial arrangements intuitively and morphologically remains limited. Therefore, in this article, a new method is proposed to characterize local characteristics by introducing a new parameter, the slope coefficient ${\beta }_l.$ This coefficient allows one to define urban spatial structure based on the similarity of local multiscale spatial distributions and explore urban evolutionary patterns. To test its validity, the city of Beijing, China, is selected as a case study. Based on six sets of remote sensing images obtained at six-year intervals from 1988 to 2018, the results show that three types of urban clusters (urban core areas, medium-sized urban settlements, and small villages and towns) dominate the urban spatial organization of Beijing. During the stage of accelerating urbanization, areas of urban growth were dominated by the expansion of urban core areas in the central urban district due to the concentration of population and abundant land resources. During the later process of decelerating urbanization, with declining population growth and limited land resources, the connectivity of urban core areas to the center and periphery, with increasingly scattered medium-sized urban settlement patterns, has become the main mode of urban growth. The findings enable us to reexamine urban spatial organization from a multiscale perspective and provide planning reference for cities experiencing rapid urbanization.

理解城市空间结构和演变模式, 对制定城市空间发展策略非常重要。多重分形分析能有效地、多尺度地研究城市空间结构。然而, 由于没有处理局部参数的有效方法, 多重分形分析在直观地、从形态上确定城市空间组成时, 受到了局限。本文提出一种新方法, 通过引进一个新的参数（坡度系数β_i）, 描述局部特征。该系数根据局部多尺度空间分布的相似度, 来定义城市空间结构, 并研究城市演变模式。为了验证该方法, 本文选取中国北京市为案例。基于1988-2018年每隔六年获取的共6幅遥感影像, 结果显示, 三种城市集群（城市核心区, 中等大小的城市居民区, 小乡镇）主导了北京市城市空间结构。在城市化加剧阶段, 由于人口集中和土地资源充足, 城市增长模式主要是位于城市中心区的城市核心区的扩张。在城市化速度减缓阶段, 由于人口增长的减慢和土地资源的限制, 中等大小的城市居住区变得越来越分散, 城市发展的主要模式是城市核心区与中心地区和边缘地区的连接程度。这些发现, 使得我们可以从多尺度的角度去重新审视城市空间结构, 为快速城市化的城市提供了规划参考。

Es crucial entender la organización espacial urbana y sus patrones de evolución para formular estrategias de desarrollo espacial. El análisis multifractal ha sido aplicado efectivamente para investigar la organización espacial urbana de manera multiescalar. Sin enfoques efectivos con los cuales lidiar con los parámetros locales, sin embargo, su capacidad para identificar intuitiva y morfológicamente la disposición espacial urbana sigue siendo limitada. Por tanto, en este artículo se propone un nuevo método para representar las características locales introduciendo un nuevo parámetro, el coeficiente de inclinación β_l: Este coeficiente permite que uno defina la estructura espacial urbana basado en la similitud de las distribuciones espaciales locales a multiescala y explore los patrones urbanos evolucionados. Para poner a prueba su validez, se seleccionó la ciudad de Beijing, China, como caso de estudio. Con base en seis conjuntos de imágenes de percepción remota obtenidas a intervalos de seis años entre 1988 y 2018, los resultados muestran que tres tipos de agrupamientos urbanos (áreas nucleares urbanas, asentamientos urbanos de tamaño medio, y aldeas y pueblos pequeños) dominan la organización espacial urbana de Beijing. Durante la etapa de urbanización acelerada, las áreas de crecimiento urbano estuvieron dominadas por la expansión de las áreas nucleares urbanas en el distrito urbano central debido a la concentración de población y a la abundancia de recursos de la tierra. Durante el proceso más tardío de urbanización desacelerada, con declinación del crecimiento demográfico y recursos de la tierra limitados, la conectividad de las áreas nucleares urbanas con el centro y la periferia, y con patrones de creciente dispersión de asentamientos urbanos de tamaño medio, se ha convertido en el modo principal de crecimiento urbano. Los descubrimientos nos permiten reexaminar la organización espacial urbana desde una perspectiva multiescalar y proveer referencia de planificación para ciudades que experimenten urbanización rápida.

Key Words:

• multifractals
• urban spatial evolution
• urban spatial organization
• urbanization

关键词:

• 多重分形
• 城市空间演变
• 城市空间结构
• 城市化

Palabras clave:

• Beijing
• evolución espacial urbana
• multifractales
• organización espacial urbana
• urbanización

Acknowledgments

The authors are grateful for all of the constructive comments and suggestions from the editors and reviewers during the peer review process.

Additional information

Funding

This study was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA19090108).

Notes on contributors

Xingye Tan

XINGYE TAN is a Doctoral Candidate in the Department of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, Hong Kong. E-mail: [email protected]. His research interests lie in urban complexity, urban spatial analysis based on big data, and urban spatial modeling.

Bo Huang

BO HUANG is a Professor in the Department of Geography and Resource Management and the Associate Director of the Institute of Space and Earth Information Science, The Chinese University of Hong Kong, Shatin, Hong Kong. E-mail: [email protected]. His research interests cover the design and development of models and algorithms for spatial and spatiotemporal statistics, unified satellite image fusion and multiobjective spatial optimization, and their applications in environmental monitoring and sustainable land use and transportation planning.

Michael Batty

MICHAEL BATTY is Bartlett Professor of Planning and Chair of the Centre for Advanced Spatial Analysis (CASA) at University College London, London, UK. E-mail: [email protected]. His research work involves the development of computer models of cities and regions, big data and smart cities, and simulating long-term structural change and dynamics in cities as well as their visualization.

Jing Li

JING LI is an Assistant Professor in the Department of Geography and Resource Management and the Deputy Director of the Center of Land Resource and Housing Policy at the Institute of Future Cities, The Chinese University of Hong Kong, Shatin, Hong Kong. E-mail: [email protected]. His research interests include housing economics, urban sustainable development, urbanization and regional disparity, cohort analysis of housing price and tenure choice, and the Belt and Road Initiative.